Sheet feeding apparatus



an. 13, 1948. L. c. WILLIAMS 2,434,530

SHEET FEEDING APPARATUS Filed June 1, 1944 2 Sheets-Sheet 1.

Jan. 13, 1948.

.n-lm i ill-lllllllll L. C. WILLIAMS SHEET FEEDING APPARATUS Filed June1, 1944 2 Sheets-Sheet 2 i INVENTOR. I g

Patented Jan. 13, 1948 SHEET FEEDING APPARATUS Leo C. Williams, PearlRiver, N. Y., assignor to Dexter Folder Company, Pearl River, N. Y., acorporation of New York Application June 1, 1944, Serial No. 538,241

17 Claims. 271-20) This invention relates to sheet feeders for feedingsheets to printing presses or other machines, and more particularly tosheet separating devices thereof employed to separate the sheets oneafter another from a pile of said sheets preparatory to forwarding ofthe sheets from said pile.

In known types of sheet feeders there is employed sheet separatingmechanism including friction devices such as, for example, a pair ofcomber wheels which are moved into engagement with the rear oppositecorners of the topmost sheet of a pile of sheets, and rotated inopposite directions to effect a preliminary separation of the sheet forfurther action thereon by suction sheet lifting devices. These comberwheels require considerable mechanism to rotate the same, and to movethem into and out of engagement with the pile of sheets in timedrelation with the sheet lifting devices. Also, in some cases,particularly with reference to certain grades of paper, the comberwheels would mark or otherwise disfigure the sheets, which isobjectionable, due to the pressure of said comber wheels on said sheetsnecessary to effect separation thereof.

In addition, because of the high speeds at which present sheet feedersare required to operate, the interval of time that the comber wheels arein contact with the pile of sheets is barely sufiicient to effectseparation of the sheets, with the result that the sheets are improperlyseparated.

It is accordingly one object of the present invention to provide novelmeans for effecting preliminary separation of a corner portion orportions of the topmost sheet of a pile of sheets without having anymovement imparted thereto andthus requires no mechanism to operate thesame.

Another object is to provide novel sheet separating means for effectinpreliminary separation of a corner portion or portions of the topmostsheet of a pile of sheets without in any way, marking or disfiguring thesheet, and wherein the sheet separating action thereof is in no Way af-.

fected by the speed at which the sheet feeder is operated- A furtherobject is to provide novel sheet separating means which utilizescompressed air for eifecting preliminary separation of a corner portionor portions of the topmost sheet of a pile of sheets.

A still further object is to provide a novel sheet separating devicewhich utilizes compressed air for effecting preliminary separation of acorner portion of the topmost sheet of a pile of sheets, and which isautomatically maintained in a predetermined relation to the top of saidpile regard- 2 a less of variations in the height or unevenness in thetop surface of the same.

Another object is to provide a sheet separating device of novelconstruction which utilizes air under pressure for preliminarilyseparating a corner portion of the topmost sheet of a pile of :heets sothat a secondary sheet handling means may operate to grip and lift saidsheet, in combination with means engaged with the pile for maintainingsaid device in a predetermined relation to the top of the pile and atthe same time acting through such engagement to hold the sheets inseparated condition and to further ensure that the top sheet alone islifted by said means.

The above and further objects and novel features of the presentinvention will more fully appear from the following detailed descriptionwhen the same is read in connection with the accompanying drawings. Itis to be expressly understood, however, that the drawings are for thepurpose of illustration only and are not intended as a definition of thelimits of the invention, reference for this latter purpose being hadprimarily to the appended claims.

In the drawings,'wherein like reference characters refer to like partsthroughout the several views,

Fig. 1 is a vertical longitudinal sectional view of a sheet feederembodying the present invention;

Fig. 2 is a fragmentary top plan view of the sheet feeder illustrated inFig. 1;

Fig. 3 is an enlarged top plan view, partly in section of one of thesheet separating devices in operative position;

Fig. 4 is a vertical sectional view on the line -4-4 of Fig. 3;

Fig. 5 is an enlarged detail perspective view of the sheet separatingdevice;

Fig. 6 is a perspective view illustrating diagrammatically the resultantaction of the sheet separating device on the sheets of the pile at onecorner thereof; and

Fig. 7 is an enlarged side elevation of one of the sheet separating andlifting units illustrated in Figs. 1 and 2.

Referring to the drawings, the novel sheet separating means of thepresent invention are shown as embodied in a sheet feeder of generalconstruction and which includes a pile elevator comprising two side barsi0, one only being shown, adapted to support a pile board II and pile ofsheets i2 (Fig. l). Pile board H and pile of sheets I2 thereon areraised intermittently in the usual manner, to keep the top of said pileat a the side frames l1 so predetermined level, by cables l3 and H atopposite sides of the feeder, which are secured to each bar In and passover grooved sheaves l5 and I6 journalled on the feeder side frames l1.Cables l3 and I4 extend downwardly from sheaves l5 to winding drums 18fixed on a transverse shaft l9 journalled in suitable bearings in framesl'l. Shaft 19 and drums l8 are intermittently rotated from any suitablesource of power and by any suitable mechanism connected with said shaftto raise bars l0, pile board II and pile of sheets l2.

The sheets of pile l2 are acted upon one after another by suctiondevices 20 (Figs. 1, 2 and 7) which are adapted to engage opposite rearcorner portions of each successive sheet and lift the rear edge thereofabove the level of the pile These suction devices are carried on arms 2|pivotally mounted in ment toward and by suitable cams 23 cam shaft 24.Casings adjustable along hollow cross shafts 25 and 26 to locate thesuction devices 20 for operation on sheets of different widths, eachcasing being secured in its desired position of adjustment by a clampscrew 21. Shafts 25 and 26 are closed at their opposite ends, and aresecured in brackets 28 which are supported by, and adjustable along.that the suction devices 20 may be moved longitudinally of the feeder asa unit for operation on sheets of different'lengths. Cam shaft 24extends through casings 22 and is journalled in suitable bearings insaid casings and in the brackets 28. Y

Vacuum is created and broken at predetermined intervals in the suctiondevices 20 to cause the latter to grip and release each sheet, and forthis purpose said devices have connected therewith corresponding ends offlexible conduits 29, the opposite ends of which are connected with thevacuum side of a rotary valve mechanism 30 (Fig. 2) supported on thehollow shafts 25 and 26. Valve mechanism 30 is of the type disclosed inthe United States Patent No. 2,233,934, granted March 4, 1941, toHeadley Townsend Backhouse, and needs no detail description herein. Thevalve mechanism is connected with an air and vacuum pump (not shown)through the hollow shafts 25 and 26 which are in communication with saidmechanism and connected in any suitable manner with the vacuum side andair pressure side, respectively, of said pump, and said mechanism isdriven from the cam shaft 24 by suitable gearing (not shown) to controlthe making and breaking of vacuum in the suction devices 20, arid thedelivery of air under pressure to sheet separating devices to behereinafter described.

Prior to release of the lifted sheets by the suction devices 20, saidsheets are engaged bysheet forwarding devices (not shown) which forwardthe sheets, when released by the suction devices, a short distance fromthe pile to conveying means indicated generally at 3| (Fig. 1) thatadvanc the sheets to a printing press or other instrumentality withwhich the feeder is associated.

Novel means are provided for effecting preliminary separation of thetopmost sheet on the pile from the next or underlying sheet prior toaction thereon by the suction devices 20, to ensure that the top sheetalone is lifted from the pile by said devices, and that the sheets areforwarded singly from the pile to the conveyor. As herein shown, saidsheet separating means are arranged at opposite rear corners andadjacent the top of the away from the top of the pile (Fig. 1) fixed ona driven casings 22 for rocking move- 22 are mounted on and this mannerthe sheet pile of sheets l2. and each preferably comprises a hollow airbox 32 (Figs. 3, 4, 5 and '7) having interconnected arms 33 and 34 whichare disposed at right angles to each other so that said box extendsalong the side and rear edges of the pile of sheets. Box 32 means in theform of a thin slot or orifice 35 directed laterally through the wall ofarm 33 facing the side edge of the pile of sheets, and a thin slot ororifice 36 directed forwardly through the wall of arm 34 facing the rearedge of the pile of sheets. Slots 35 and 36 extendvertically of the airbox 32 and crosswise or vertically of the plane of the sheets in thepile, and are preferably spaced approximately an inch and three quartersfrom the corner formed by the'walls of said box. The slots providestrong, thin elongated jets of air issuing from said slots, and thelatter are preferably of a length such that, when the air box is inproper position to effectively separate the sheets, the lower ends ofthe slots are approximately three-quarters of an inch below the top ofthe pile of sheets, and the upper ends of said slots are approximatelythree-eighths of an inch above the level of the pile.

Each corner sheet separating device is arranged in'the feeder in a novelmanner for automatic adjustment in a vertical direction to compensatefor variations in the height of the pile of sheets or unevenness in thetop surface of the pile. In separating devices are in dependentlymaintained in proper relation with respect to the top of the pileregardless whether the pile is high or low, or the surface thereof isunevemthus ensuring accurate preliminary separation of the rear cornerportions of the sheets at all times and under all conditions. As shown,

each air box 32 is supported and guided for floating movement in avertical direction and parallel with the side and rear edges of thepile, by a rigid conduit 31 (Fig. '7) that is welded to the box at thecorner and extends upwardly through a suitable opening formed in anextension 38 of casing 22; Conduit 31 communicates with the interior ofbox 32 and is provided on its upper end with a nut 39 threaded thereonto retain said box on casing 22 during loading and reloading of thefeeder with a pile of sheets.

Each air box 32 is provided with pile engaging means which, asillustrated, is preferably in the form of a rod or wire 4i] (Figs. 3, 4and 7) that extends diagonally across the corner of said box and issecured at its opposite ends, as by bolts 4|, to the inner walls of arms33, 34 at points between the slots 35, 36. Rod 40 is preferably bentintermediate its ends in the form of a V so as to provide point contactof said rod with the top of the pile directly at the corner thereof, andsaid rod so located vertically on box 32 that when engaged with the topof the pile, the slots 35, 36 will be disposed in proper position aboveand below the level of the pile as hereinbefore described is providedwith air let thereby preventing angular displacement of the latter withrespect to said casing and the corner of the pile of sheets. Bars 42 and43 are retained upon casing 22 by pins 44 extending through the upperends of said bars and resting on the extension 38. The space betweenbars 42 and 43 is slighty greater than the thickness of arm 1 a 33 so asto enable free floating movement ofethe air box in a vertical direction.

The preferred position of each air box with respect to the side and rearedges of the pile of sheets is approximately three-eighths of an inchaway from said edges. This position is automatically determined withrespect to the sides of the pile by the bars 43, each casing 22 and airbox carried thereby being adjusted separately along shafts 25 and 26until the bar lightly engages the adjacent side edge of the pile. Afterthe casings and air boxes are adjusted as described, they are adjustedlongitudinally of the feeder as a unit until the rods 40 engage the topof the pile of short distance diagonally inward of the corners thereof,said adjustment automatically determining the position of the air boxeswith respect to the rear edge of the pile.

Air under pressure is delivered to the air boxes,

32 at predetermined intervals in timed relation with the operation ofthe suction devices 20, and.

whereupon the air to the boxes 32 is discontinued through continuedrotation of valve mechanism until the next cycle of operation of thefeeder at which time the next and underlying sheets i are againsubjected to the twojets of air. When the top sheet is lifted from thepile by the suction devices 20, the corners of said sheet are drawn frombeneath rods 40 which then engage the underlying sheet and hold or stripthe latter from the top sheet should there be a tendency of theunderlying sheet to stick to the topsheet.

Due to engagement of rod 40 with the top of the pile, the cornerportions of the sheets as separated during the initial cycle ofoperation of the feeder are maintained in such separated condition bysaid rod, and in this manner little effort is required of the jets ofair to complete the separation of the next and succeeding sheets duringthe next and succeeding cycles of operation of the feeder.

The bars 43 substantially close the space between arms 33 and the sidesof the pile and thus serve as additional bafiles to obstruct the escapeof air. It will be understood that similar bafiies may be used upon thearms 34 if desired, and that other baflies may also be used on both armsif it is desired to further obstruct the escape of air.

, Further, the relative positions of the slots 35 and points spaced fromthe corner thereof and tend to rebound and if permitted to escape willlose much of their effectiveness. However, the walls of arms 33, 34facing the pile form bafile means which obstruct or restrict the escapeof air, thereby causing the air to penetrate the pile and enter betweena plurality of the uppermost sheets. The air projected into the pilefrom the two angularly related points engages or intermingles betweenthe sheets at a point spaced inwardl from the corners thereof and setsup eddying or whirling currents of air which turbinate toward the outeredges of the sheets, the escape of the air from between the sheets beingobstructed or restricted by the arms 33, 34. The corner portions of thesheets thus acted upon will raise or fluff up and become separated onefrom another in a progressive manner beginning with the lowermost sheetand ending with the uppermost or top sheet, with the maximum amount ofseparation being between the top sheet and the next or underlying sheet,as shown in Figs. 4 and 6, at the same time assuming a humped condition,as indicated at 46 (Figs. 4 and 6), due to engagement of rod with thetop of the pile, the corner of the top sheet and of a few of theunderlying sheets sliding slightly relative to said rod during saidseparation, but not sufiiciently to become disengaged therefrom.

When the jets of air have separated the opposite rear corner portions ofthe top sheet as described, the suction devices 20 are operated to gripsaid sheet at the raised humped corner portions and further lift thesheet'from the pile, 76 of the same.

. clear to those skilled in the art.

36 above and below the top of the pile may be varied by relocating orbending the rod 40.

There is thus provided a novel, simple and inexpensive sheet separatingdevice for eiTecting positive and accurate preliminary separation of acorner portion of the topmost sheet of a pile of -sheets, which utilizesair under pressure for this purpose, and thus requires no movement to beimparted thereto and consequently no mechanism to operate the same.Additionally, the sheet separating device is automatically maintained ina predetermined relation to the top of the pile regardless of variationsin the height or unevenness in the surface of the pile, thus requiringno further handling of the device after once set in operative position.Also, the sheet separating device will effectively separate the sheetswithout in any way marking or disfiguring the sheets, and

the action thereof is in no way affected by the speed at which thefeeder is operated.

Although only a single embodiment of the invention has been illustratedand described in the foregoing specification, it is to be expresslyunderstood that changes may be made therein particularly in the designand arrangement of the parts illustrated, without departing from thespirit and scope of the invention, as will now be For a definition ofthe limits of the invention, reference is had primarily to the appendedclaims.

What is claimed is:

1. A sheet separator forpreliminarily separating a corner portion of asheet from a pile of sheets for action of other sheet handling meansthereon and comprising means providing two jets of air of substantiallength extending crosswise of the plane of the sheets and directedtoward adjacent sides of the pile at points spaced from a cornerthereof, bafiie means extending between the two jets, means for guidingsaid jet means for floating movement in a vertical direction andparallel to said sides of the pile, and means engaged with the top ofthe pile for automatically maintaining said jet means in a predeterminedrelation to the top ofthe pile regardless of variations in the height orunevenness in the surface 7 2. In a sheet feeder, a sheet separatingdevice for preliminarily separating a corner portion of a sheet from apile of sheets for action thereon of other sheet handling means andcomprising means providing two jets of airof substantial lengthextending crosswise of the plane of the sheet and directed towardadjacent sides of the pile at points spaced from a corner thereof,baffle means extending between the two jets, means for guiding said jetmeans and said baille means for floating movement in a verticaldirection and parallel to said sides of the pile, and means engaged withthe top of the pile at the corner thereof for automatically maintainingsaid jet means and said baffle means in a predetermined relation to thetop of the pile and such that each jet of air extends above and belowthe level of the pile.

3. In apparatus of the class described, air blast means forsimultaneously separating corner portions of a plurality of sheets froma pile of sheets, means for rendering said air blast means opera tiveand inoperative at predetermined intervals, and means engaged with thepile at the corner thereof for causing said separated portions of thesheets to assume a humped condition upon separation thereof by said airblast means and for holding said portions in said condition when saidair blast means is rendered inoperative.

4. In a sheet feeder, air blast means for directing two elongated jetsof air at an angle with respect to each other against the edges of apile of sheets contiguous a corner thereof to separate a corner portionof the top sheet from said pile of sheets, bafile means associated withsaid air blast means and extending between said air jets, means foryieldably holding the corner of said sheet engaged with the pile tocause said portion of the sheet to assume a humped condition uponseparation thereof by said air blast means, and suction means forengaging said separated humped corner portion of the sheet and liftingsaid sheet from the pile.

5. In sheet feeding apparatus of the type havingmeans for supporting apile of sheets, the combination of air blast means for separating aplurality of said sheets simultaneously one from another adjacent acorner thereof, means for controlling the delivery of air under pressureto said air blast means at predetermined intervals, and means forholding the sheets in separated condition when the air to said air blastmeans is discontinued.

6. In apparatus of the class described having suction means adapted toengage the top sheet of a pile of sheets and lift said-sheet from saidpile, the combination therewith of air blast means for separating acorner portion of said sheet from the next or underlying sheet, andmeans for yieldably holding the corner of the top sheet engaged with thepile to cause the separated portion to assume a humped condition forengagement by said suction means, said holding means also serving toprevent movement of the underlying sheet with the top sheet when thecorner of the latter is drawn from beneath said means and lifted by saidsuction means.

'7. A sheet separator for preliminarily separating a corner portion of asheet from a pile of sheets for action of other sheet handling meansthereon and comprising an air box having a pair of walls disposed atright angles to each other, means in each of said walls and spaced fromthe corner of the pair of walls for providing a thin jet of air ofsubstantial length extending crosswise of the plane of the sheets, meansfor supporting said air box adjacent a corner of the pile of sheets andfor floating movement in a vertical direction parallel to adjacent sidesof said pile, and means carried by said air box and engaged with the topof the pile of sheets for automatically maintaining the air box in apredetermined relation with respect to the top of said pile.

8. In a sheet feeder, means for preliminarily separating a cornerportion of a sheet from a pile of sheets for action thereon by othersheet handling means and comprising an air box having a pair of wallsdisposed at right angles to each other, an elongated vertical slot ineach of said walls and spaced from the corner of said pair of walls,said slots providing thin jets of air of substantial length extendingcrosswise of the plane of the sheets, means supporting said air boxadjacent a corner of the pile of sheets and for floating movement in avertical direction parallel to adjacent sides of said pile, and meansengaged with the top of the pile for automatically maintaining the airbox in a predetermined relation to the top of said pile, said last-namedmeans comprising a member secured to said air box and extendingdiagonally of the corner of the latter and the corner of the pile ofsheets.

9. In apparatus of the class described, means for preliminarilyseparating opposite corner portions of a sheet from a pile of sheets foraction thereon by other sheet handling means and comprising twolaterally spaced air boxes each having a pair of walls disposed at rightangles to each other, an elongated vertical slot in each of said wallsand spaced from the corner of the respective pair of walls, said slotsproviding thin jets of air of substantial length extending crosswise ofthe plane of the sheets, means supporting said air boxes adjacentopposite corners of the .pile of sheets and for floating movementindependent of each other in a vertical direction and parallel toadjacent sides of the pile, and means engaged with the top of the pilefor automatically adjusting the air boxes independently of each other toaccommodate variations in the height and irregularities in the surfaceof the pile at said corners.

10. In apparatus of the class described, means for directing a thinvertical jet of air against one side of a pile of sheets and adjacentone corner thereof, whereby a corner portion of the top sheet of saidpile is separated from the sheets therebeneath, means engaged with thetop of the pile directly at said corner for yieldingly resisting theseparating movement of said corner portion of the top sheet, and suctionmeans for engaging the separated corner portion of the sheet and liftingsaid sheet from the pile.

11. In combination, means for directing at least two thin vertical airjets against the edges of a pile of sheets adjacent to the cornersthereof that lie in a single line, means engaged with the top of thepile directly at the corner for yieldingly resisting upward movement ofthe corner portion of the top sheet from the pile by said air jets, andsuction means for engaging said corner portion of the sheet and liftingsaid sheet from the pile.

12. In a sheet feeder, means for intermittently directing two air jetsat substantially right angles to each other against the sides of a pileof sheets adjacent one corner of the pile, means engaged with the top ofthe pile at said corner for resisting the movement upward from said pileof the corner portion of the top sheet, and means for engaging saidcorner portion after it has been moved from the pile by said air jets.

13. In a sheet feeder, a sheet separating device for separating a cornerportion of a sheet from a pile of sheets comprising means providing atleast one jet of air of substantial length extending crosswise of theplane of the sheets adjacent one corner thereof, bafile means associatedwithsaid jet means, means guiding said jet means for vertical movementin a plane parallel to but spaced from the adjacent side of the pile,and means engaged with the top of the pile for automatically maintainingsaid jet means in a predetermined relation to the top of the pileregardless of variations in the height or unevenness in the surface ofthe same. 9

14. A sheet separator for separating a corner portion of a sheet from apile of sheets for action thereon of other sheet handling meanscomprising means providing at least one jet of air of substantial lengthextending crosswise of the plane of the sheets adjacent one cornerthereof, baffle means associated with said jet means, means for guidingsaid jet means and said baflle means for vertical movement in a planeparallel to but spaced from the adjacent side of the pile, and meansengaged with the top of the pile for automatically maintaining said jetmeans and said baflle means in a predetermined relation to the top ofthe pile and such that the jet of air extends above and below the levelof the pile.

15. In a sheet feeder, a sheet separating device for separating a cornerportion of a sheet from a pile of sheets comprising means providing atleast one jet of air of substantial length extending crosswise of theplane of the sheets adjacent one corner,thereof, ballle means associatedwith said jet means and extending along adjacent sides of the pile atsaid corner, means guiding said jet means and said bailie means forvertical movement in a plane parallel to but spaced from the adjacentsides of the pile, and means engaged with the top of the pile at saidcorner for automatically maintaining said jet means and said bafilemeans in a predetermined relation to the top of the pile and such thatthe jet of air extends above and below the level of the pile.

16. In apparatus of the class described, air blast means for separatinga corner portion of the top sheet from a pile of sheets, means mountedfor floating movement in a vertical plane for yieldably holding thecorner of said sheet in engagement with the pile to cause said portionof the sheet to assume a humped condition upon separation thereof bysaid air blast means, and suction means for engaging said separatedhumped corner portion of the sheet and lifting said sheet from the pile.

17. In apparatus of the class described, air blast means for separatinga corner portion of the top sheet from a pile of sheets, means mountingsaid air blast means for floating movement in a vertical plane andparallel with the vertical projection of the pile, and means engagedwith the top of the pile at'the corner for maintaining said air blastmeans in a predetermined relation with respect to the top of the pileand for causing said corner portion of the sheet to assume a humpedcondition upon separation thereof by said air blast means.

LEO C. WILLIAMS.

REFERENCES CITED The'following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,493,167 Stevens May 6, 19241,289,051 Lane et al Dec. 24, 1918 1,457,094 Thompson et a1 May 29, 19232,108,702 Backhouse Feb. 15, 1938 1,867,038 Upham July 12, 19321,585,368 Blaine May 18, 1926 1,498,965 Henderson June 24, 19241,112,609 Harris Oct. 6, 1914 1,567,372 Jacobson Dec. 29, 1925 FOREIGNPATENTS Number Country Date 617,838 Germany Aug. 27, 1935. 396,285 GreatBritain Aug. 3, 1933 490,906 Great Britain Aug. 23, 1938 7,503 GreatBritain Apr. 10, 1899 7,573 Great Britain Apr. 6, 1908

